[Fuchs' heterochromic cyclitis without heterochromia: a diagnostic approach].

OBJECTIVE To obtain diagnostic guidelines of Fuchs' heterochromic cyclitis (FHC) in the absence of heterochromia using Bayesian methods. METHODS The pre-test and post-test likelihood that a certain patient without heterochromia (but with other characteristic symptoms of the disease such as iris nodules, cataracts, glaucoma or vitritis) has FCH, was assessed by the Bayes' theorem for conditioned likelihood. The prevalence values of FCH and the presentation rate of symptoms in FCH and in other forms of anterior uveitis were obtained from published literature data. RESULTS In the absence of heterochromia, the combination of iris nodules together with cataracts, vitritis or glaucoma, and the association of the last three symptoms in the absence of nodules, resulted in an accumulated likelihood of more than 50% of subjects having the disease. CONCLUSIONS The coincidence in one patient of several indicative symptoms, even in the absence of heterochromia, may make FCH a likely diagnostic option.